


Once Upon A Time...

by AtowncalledMalec



Series: Tentacletober [23]
Category: Shadowhunters (TV), The Shadowhunter Chronicles - All Media Types, malec - Fandom
Genre: Alpha Alec Lightwood, Alpha/Beta/Omega Dynamics, Alpha/Omega, Alternate Universe - Fairy Tale, Anal Fingering, Anal Sex, Angst with a Happy Ending, Consent is dubious, Fairy Tale Style, Fuck Or Die, HEA, I've never steered you wrong yet, Implied Mpreg, Implied/Referenced Dubious Consent, M/M, Mating Cycles/In Heat, Merman magnus, Mutual Pining, Omega Magnus Bane, Sea Witch Alec, Tentacles, Trust the author?, but it also isnt, idk - Freeform, induced heat
Language: English
Status: Completed
Published: 2019-11-02
Updated: 2019-11-02
Packaged: 2021-01-20 20:57:55
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 9,130
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21288077
Author URL: https://archiveofourown.org/users/AtowncalledMalec/pseuds/AtowncalledMalec
Summary: Once upon a time, in a kingdom far far away...The fairytale AU that nobody asked for.When the wards that surround the Kingdom of Atlantis threaten to fall, it is down to Crown Prince Magnus to mate and marry a powerful Sea Witch in hopes of saving his kingdom. Unfortunately, he doesn't have much choice in the matter as his father is the one who arranges it behind his back. Just when Magnus thought it couldn't get any worse, he meets his true Alpha before the ceremony.This work is not to be reposted anywhere else or translated without my permission.
Relationships: Magnus Bane/Alec Lightwood
Series: Tentacletober [23]
Series URL: https://archiveofourown.org/series/1502561
Comments: 33
Kudos: 347
Collections: Favorite Malec Stories, Tentacletober





	Once Upon A Time...

**Author's Note:**

> Ahem... better late than never?
> 
> Prompt #28 Fuck or Die Tentacle Sex and #21 Tentacle Angst.
> 
> Warning. I've tagged this one dubcon because Magnus has to mate against his will. But like any good fairytale, all is not what it seems. I'm not gonna lie, there's a lot of angst and dread in this one, and it gets a bit Brothers Grim in the middle but there's a happy ending. 
> 
> If you can't read that then please don't.

Prince Magnus of Atlantis had always known what to expect from his life. It had been ingrained in him since birth, drummed into his head and spoken of as a matter of fact that he would one day be King of Atlantis.

To most, Magnus’ life looked to be one of great happiness and privilege. His family’s Kingdom was spread across a beautiful island, surrounded by mountains that looked out over the ocean. The palace he lived in, built into those mountains, the complex running the breadth of them, was sprawling and comfortable and housed many of his people. He also had a large family. 

Magnus was the youngest member of the royal family and had twelve brothers and sisters. As a Prince and future King, he was afforded many luxuries, able to swim all day in the ocean if he wanted to or visit the town that sat within the protective ring of mountains. Clothes, pearls, fine food, and drink were all at his disposal whenever he wished for them. He even had a small amount of magic.

Those things should have made Magnus happy. He had a life that most merfolk would happily live. But he also had his problems. 

Like the fact that his brothers and sisters were selfish and spoiled, and treated their people as though they were simply there for the royal family’s amusement. 

Like the fact that his future was not his own to decide. 

Like the fact that his father was a cruel merman who held no regard for Magnus’ or any of his children’s wishes.

Like the fact that he was the only Omega amongst his siblings and therefore was fated to rule over his Kingdom when the time came.

And so it was that Magnus found himself a victim to that future one fateful day. The day he turned 100 years old. 

Magnus had never been told exactly when he would take his father’s place. His hundredth birthday was not what he had expected. But he had been summoned and his father had laid out his plan. As much as he had prepared himself for it, there was no easy way to digest his father’s orders.

Standing in the throne room on that day, Magnus stared at his father. The words washed over him, refusing to sink into his stunned brain. He didn’t even hear half of what Asmodeus was saying to him. For some reason, he had thought he had more time. The future was always a distant thing. Until it wasn’t.

“No,” Magnus said, cutting his father off, refusing point-blank to be part of Asmodeus’ ridiculous plan. In his mind, he had always thought that he would get to choose for himself. Nobody had ever mentioned this part. “I won’t do it. When I find a mate, it will be for love, not politics,” he said furiously.

“No?” Asmodeus asked, his voice dangerously low. The determined expression on his willful son’s face had his eyes narrowing. “You are a prince, Magnus. Princes do not get to mate for love. They do their duty by their Kingdom. He will be here tonight. You  _ will _ mate him and you  _ will _ marry him in four days’ time,” he said, ending the discussion.

“If our Kingdom needs him so badly,  _ you _ can marry him!” Magnus yelled, fighting the urge to wrap his hands around his father’s neck. 

“Why can you never do as you are told?” Asmodeus snarled, losing his patience. The approach of his aid, Ragnor, stopped him from bounding up from his throne when Magnus turned on his heel and stalked out of the throne room. 

“Your Majesty, please,” Ragnor said, raising his hand to placate the King. “I will talk to him,” he said before following Magnus out of the room.

“Your Highness, wait!” Ragnor huffed, trying to keep up with the younger merman’s breakneck pace. 

“Who’s side are you on?” Magnus asked, whirling on the man he’d counted as a friend since he’d been old enough to swim on his own.

“Yours. I’m on your side, Magnus. But your father is right, the Kingdom needs this marriage. Without the Sea Witch, we are doomed,” Ragnor said, running down the steps of the palace to the water's edge to keep up. “We need his magic. Without it, we will all perish.”

“Why me though?” Magnus asked, shrugging his clothes off. He’d lost count of how many times he had asked that over his lifetime.

“Because, as your father said, you are a Prince of the Kingdom. The Sea Witch is a royal. Only a royal marriage will do. You’re the only Omega, Magnus. It has to be you,” Ragnor said sadly. 

Ragnor wanted nothing more than for his friend to mate for love. Unfortunately, the magic that surrounded their Kingdom was slowly disintegrating. Without an infusion of new magic, the humans would find Atlantis and all would be lost.

Magnus threw himself into the sea, needing to get away from it all. Short-lived relief flooded him when the gills on his neck opened up and he transformed his boring human legs into his sparkling red tail. His scales gleamed in the dim sunlight that shone through the water. The relief didn’t reach his heart.

Magnus swam as fast as his tail could propel him, swam until his fins burned and his gills ached. The physical discomfort was a nice distraction from the pain in his heart. Until it wasn't.

Finding his favorite hideaway; a small reef that he always swam to when the pressures of being a Prince invaded, Magnus collapsed onto a rock. 

Not for the first time, Magnus wished that he had been born an Alpha or a Beta. Unfortunately for Him, only Omegas were allowed to ascend the throne. Being the one who carried the young, it was the only way to guarantee that the royal line would continue. 

Any merperson could claim that an Alpha king was the father of their young and without any way of being able to disprove the claim other than denial, the bloodline could be lost. 

Becoming the King of Atlantis had been Magnus’ birthright since the day he was conceived. But that day had always been distant, something that he could push aside; deal with it when it came.

_ And now that time has finally arrived,  _ Magnus thought bitterly. What were his choices? Be selfish and refuse his father's orders, in turn letting all of the people he loved die. Or mate this Sea Witch and spend eternity with someone who wasn’t his true mate.

_ Some choice,  _ Magnus silently grumped. It wouldn’t be so hard if he didn’t love his people or care about his Kingdom. But, as much pressure as there was heaped upon him due to his position, he would do anything for them. Even if it meant mating some strange Sea Witch.

A stirring in the water behind him had Magnus turning to see what the commotion was. The sight that greeted him had his heart pounding and his stomach sinking.

The most beautiful creature Magnus had ever seen floated before him, a male, he noted when his eyes wandered over the humanoid upper portion of the creature’s body. Muscular with strong arms, wide shoulders, curls of hair on his firm looking chest, and chiseled abdominal muscles. Pale skin, he noted, until his eyes wandered lower. The creature’s skin turned dark below the navel and ended with eight thick black tentacles.

Alec stared at the merman, his eyes roving over the black hair and beautiful golden eyes. The red scales that bracketed the merman’s eyes and face trailed down his neck and the sides of his muscular chest, cascading down the smoothe golden skin of his chest and stomach, thickening until they reached below his navel. The gleaming red tail was beautiful.

Alec’s gaze was drawn back to the merman’s eyes. A shiver of recognition shot through him and broke his heart. This was his mate, the one who had been made to complete him. Unable to stop himself, he ingrained every detail of the merman into his brain, desperately wanting to reach out and touch him, to run his fingers over those beautiful scales.

One look into the creature’s beautiful hazel eyes was all it took for Magnus to know, down to the tips of his fins, that this creature was his mate. He had never seen anything like him before and had always assumed that his mate would be a merperson too. But the pull he felt in every part of his body told him he had been wrong.

Magnus swam forward, following the pull that had taken ahold of his tail. He couldn’t stop himself when he saw the same recognition in the creature's eyes. The recognition of the other half of oneself. He raised his hand when one tentacle reached for him, a shudder running through him when the tentacle caressed his palm. It had his eyes slamming shut.

Alec couldn’t look away. Shocks ran through his tentacle, skittering up the appendage and coiling through his body. He had never desired anything more than the creature in front of him. If this is what it felt like just touching the merman’s hand... he was desperate to know what it felt like to touch the rest of him.

The reality of Magnus’ situation crashed through the sensation of the creature’s touch. A touch that felt so right. A touch that he couldn’t have. Magnus couldn’t have this extraordinary creature. He was an Omega Prince of The Kingdom with an intended mate that had been arranged by his father. 

The hurt that Magnus saw in those penetrating hazel eyes when he opened his own and swam back with a shake of his head would haunt his dreams as surely as the knowledge that he had a true mate that he could never have. Maybe he imagined it but he was positive that he saw acceptance in those eyes when he retreated.

That hurt Magnus more than the pain that the expression had replaced. He couldn’t even ask his mate’s name, unable to speak underwater. With the sting of tears and a desperation that threatened to take control of him, he forced himself to leave, to swim home before he did something that he couldn’t take back. His people were depending on him.

Alec watched the merman go, having to fight his entire body. All he wanted to do was follow the merman, to chase him and wrap him up in his tentacles and never let go. The urge was primal, a deep-seated need to chase and capture and claim his mate. The expression in his mate’s eyes had spoken of that recognition too. And then it had been replaced with despair. 

As much as Alec wanted him, he couldn’t have his mate. That wasn’t his future. The choice to mate who he wanted wasn’t his future. His father had seen to that. And to chase after the merman would only hurt them both. So he held himself back, showing a restraint that he had never known he possessed. 

**

Magnus lay on his bed, staring up at the ceiling of his bedchamber. In all of his years, he had never wished more that he had been born as a common merman without the responsibility of his people weighing his shoulders down. Sure, he had everything he could possibly want.

The large bedchamber that Magnus called his own was opulent, the pink cavelike walls decorated with driftwood and shells, artwork made by the finest artisans amongst his people. The bed he lay on, made of driftwood and a seagull feather mattress was huge, the epitome of luxury. He had the finest clothes, ate the finest food and drank the finest kelpie wine. But he didn’t have his freedom. 

The luxuries were just things. The lure of them faded away when Magnus thought of what he  _ could _ have. He would happily swap it all for the chance to find true happiness with his mate. A small home with the creature he had met earlier, maybe with a couple of merchildren swimming around, sounded like a dream compared to what he was now facing. 

The time crept ever closer, Magnus realized when a timid knock on his door snapped him from his reverie. He was pretty sure he would hear the creak of his door opening in his nightmares. Two of his father’s servants, Esmarelda and Darla, peeked around the door. 

Magnus watched the servants approach with a heavy heart, the rest of him numb. They were here to make him look pretty for his new husband. The thought made his lip curl with contempt. He considered fighting his way out of the palace, running to the water’s edge and jumping in. He considered leaving the Kingdom far behind, finding his mate and living the life that was meant for him. For them. 

And then Magnus considered what would happen to his people if he did that. The magic that surrounded their Kingdom would fall. The humans would come and destroy everything that they had built. They would all be hunted and hung upon their mantles like trophies. His people would be prodded and poked and made to do tricks to please the humans.

That was something Magnus couldn’t live with. So he let the servants come. The pity that he saw in the two females’ eyes had him looking away when they each took one of his hands and led him into his washroom. He endured it when they silently scrubbed his body down with sea salt scrubs, thoroughly, and washed his hair. He endured it when they made him stand under the waterfall in his washroom and rinsed him off.

Magnus endured it when the merwomen placed necklaces made of shells on his neck and bracelets on his wrists and ankles. And he endured it when they put charcoal on his eyelids and powdered pearl on his cheeks to make the red scales that framed his eyes and face sparkle. When they brought the robe out of his closet, however, he balked. 

The robe was beautiful, something that Magnus would usually love to wear. It was deep blue, the material sheer with a single silver clasp that would hold it together just below his navel. Pearls and seashells had been hand-stitched into the material in beautiful swirling patterns and a train would trail behind him when he walked. 

But it would leave him exposed to this stranger that he was supposed to mate. And he already felt raw and exposed.

When Magnus had been younger, he had heard whispers that the humans mated differently than merfolk. The rumors said that the humans waited weeks, got to know each other before they first mated. It had seemed odd and fantastical to him. When merfolk mated, they would mate first and then exchange vows after the union was consummated.

Right now, looking at the robe that the two merwomen held between them, Magnus thought that the human way of mating would be preferable. As soon as he was ready, the Sea Witch would arrive. 

Magnus would be expected to consummate their union for three days, until he was pregnant with a child that would unite his Kingdom with that of his intended. On the fourth, they were to be married and the Kingdom was to be turned over to them. 

For one wild moment, Magnus thought that he could put it all off by refusing to don the robe. 

“Your Highness, please. You know what he will do to us…” Darla said quietly, wishing that she was doing anything other than the task that the King had set for her. Both she and Esmarelda would rather clean out slop pots or gut fish than ready the Prince for his mating.

“Yes, I do,” Magnus said, standing up and holding his arms out. His father was not a kind merman and the two merwomen would face worse than cleaning out slop pots if they didn’t have him ready soon.

“When he comes to you, just imagine that you are with someone you love,” Esmarelda whispered in Magnus’ ear as she helped Magnus into the robe and secured it with the clasp at his waist. Her heart broke for him when Magnus grasped her hand and smiled a tight-lipped smile.

Magnus sat down on the stool in front of his vanity, gazing at his reflection. The crown, when it was placed on his head had never felt heavier. It was beautiful, a thick band of silver that was encrusted with pearls of every color. He was expected to wear it at functions and galas but he usually got to take it off any time he wasn’t needed in an official capacity. 

Once Magnus was crowned as the new king of Atlantis, he would never be able to take it off again. 

“If it helps, he is beautiful,” Darla said, fussing over the crown so it sat correctly in Magnus’ carefully spiked hair.

“He’s here already?” Magnus asked, his eyes flicking up to look at the two women in the reflection of his mirror.

“He’s waiting in a chamber down the hall. He is beautiful. And he doesn’t look cruel,” Esmarelda said, squeezing Magnus’ shoulders. When the door opened, she let go and stepped back with Darla, silently wishing the Prince luck.

“Thank you ladies, I will take it from here,” Ragnor said, carrying a tray into Magnus’ bedchamber. He dismissed the servants with a look, frowning when they hovered until Magnus nodded to them.

When the two merwomen left, Ragnor signaled for more servants to enter and set up a table with enough food and drink to keep the Prince and his new mate going for the next three days.

“I’m sure you will grow to love him, Magnus. Your mother fell in love with your father,” Ragnor said, setting the tray down on the vanity when the last of the servants left.

“Is that example supposed to make me feel better? My mother killed herself, rather than stay mated to him. She gave him 13 children, impregnated him again and again until he had his precious Omega. And then he was done with her. Through it all, he never showed her an ounce of kindness. She might have grown to love him but he never loved her,” Magnus said, his gaze boring into Ragnor’s in the mirror.

“Believe me, if I could change this law, I would. Your siblings are horrible, spoiled brats. It should have been one of them,” Ragnor said.

“It shouldn’t have been any of us,” Magnus said, agreeing that his siblings were spoiled brats. Each of them thought the Kingdom was owed to them and would happily run it into the ground with their selfish ways. He was the only one who had never wanted the crown and yet, he loved their people the most.

“Do you think he would have been different if he’d been allowed to mate for love?” Magnus asked, watching Ragnor fuss over the tray he had brought in.

“Perhaps. Your father wasn’t always like this. If you’d known him before... But the magic was failing, as it does every hundred years. Your grandfather needed an heir so he did his duty,” Ragnor said, pouring the potion he had made into a golden goblet. 

“So I get to end up just like him? Will I hate my husband too?” Magnus asked, eyeing the goblet. The potion would kick his heat off, taking away his last choice. It would also help him conceive within those three days, make him more fertile and desperate until he was with child. 

“You know, taking this potion is a choice, Magnus. I know that it seems as though all of your choices have been taken from you. But by choosing to drink this, you are choosing to face this future with your head held high,” Ragnor said, placing the goblet before Magnus. The real choice was whether Magnus would let himself be pulled down by despair or accept the circumstances he was born into.

Magnus grabbed the goblet and threw the grim tasting contents back in two gulps before dropping it onto the tray. “That isn’t a choice, Ragnor,” he said, turning away from his friend. He didn’t blame Ragnor. It wasn’t his friend who decided on the laws of their people.

“When the time comes, in 100 years, my child will have a choice. If their mate isn’t a royal then so be it. Half of a royal line is better than forcing my child to mate for anything other than love,” Magnus said, standing up and dismissing Ragnor. It wouldn’t be long before the potion kicked in and he wanted a minute alone.

“That’s what your father said,” Ragnor said quietly as he gathered the tray. He watched Magnus wander over to the tall windows that filled the wall behind Magnus’ bed, breathing a little easier when Magnus stood tall with his head held high. When Magnus turned his back, he left the room, preparing himself to let the Prince’s new mate know that Magnus was as ready as he was ever going to be.

Magnus stared out of the windows, his arms folded across his chest, as though he could hold himself together. The view was magnificent, the entire Kingdom spread out below him. But he didn’t see it. Not today. 

Instead, Magnus closed his eyes and told himself that he would accept the mate that his father had chosen for him. Accept the Sea Witch into his bed, even if he couldn’t accept him into his heart. It wasn’t his future husband’s fault, nor was it his choice. They were both following the dictates of their fathers, he had found out upon returning to the palace. 

Magnus had mated with others that he didn’t love before. He could do it again. Of course, he hadn’t mated himself  _ to _ them. There was a vast difference between sex and mating yourself to someone for life. But he wouldn’t do to his intended mate what his father had done to his mother. The image of his true mate floated behind his closed eyelids. It seemed his day wouldn’t be complete without him torturing himself first.

When the door behind Magnus creaked open, his stomach turned to stone. It felt like the patch of ground below him was falling away and his only choice was to cling onto the ragged edges left behind with his fingertips. 

Alec stepped into the bedchamber of his future mate, dread curling in his stomach. As he closed the door behind him, a small part of his brain registered that the room was nice, as was the rest of the palace. But the room wasn’t what he focussed on. What he did focus on was the merman before him. 

Alec couldn’t see the merman’s face, his future husband stood with his back to him, staring out of the windows. His new husband had black hair and broad shoulders, much like his true mate. The merman he had met that afternoon. Wasn’t it typical that his mate would come along after he pledged himself to this stranger? After it was already too late. 

The fact remained, it was too late so Alec forced himself to utter the speech that he had prepared. Even if it ripped his heart in two to say the words that would condemn him to a life without his one chance at happiness. He was forced to talk to the merman’s back but he understood the other Prince’s reluctance to turn around.

A low, deep voice reached Magnus through the fog of misery that threatened to cloud his brain. Something about it grounded him, soothed his clenching stomach. It was a beautiful voice.

“I know that you didn’t choose this but I want you to know that I will never force you. I would never have chosen this if there was ever a real choice to be made. If you want, we can pretend that we mated. Nobody has to know that we didn’t. Once they place us on the thrones there’s nothing they can do about it. I… I would like us to at least be friends,” Alec said from the doorway.

“I’ve already taken a potion that will start my heat. We’ll be stuck in this room for the next three days and we both know that we won’t be able to stop ourselves once it kicks in. There will be no pretending,” Magnus said, refusing to turn around and look at his future. 

Alec’s stomach quit flopping around for a heartbeat when he heard the merman’s soft, husky voice. It was beautiful. Until what the merman had actually said registered. Then his stomach dropped. He didn’t want to force himself on this stranger, or for the stranger to do the same out of no choice of his own.

“That won’t do you any good. They probably locked it with complex magic the moment you stepped in here,” Magnus said when he heard his future husband try the door handle. No matter how hard the Sea Witch rattled the handle, it wouldn’t open. Not until they were done. At least the Witch tried to get out, tried to put a stop to it. It made him feel a little better about the situation.

Alec snapped his fingers, trying to undo the spells that had been placed on the door. It wouldn’t work. He sent his magic out, stroking over the spells, trying to find a loophole or weak spot but there were none. 

Considering they needed fresh magic for the Kingdom, someone was sure going to a lot of effort to keep them locked in there. Alec suspected it was the King. They had met briefly when he’d arrived, ahead of the rest of his family, and he’d disliked the merman instantly.

“Then will you consent to mate me?” Alec asked, giving up on trying to get out of the locked door. There were too many spells woven into the door, it would take too long to dismantle all of them. By the time he got through them, it would be too late. They wouldn’t have much of a choice when the Prince’s heat started. Asking now was the best he could do.

“Yes, I will consent,” Magnus said, closing his eyes once more to fight the lump in his throat. He had to force the image of his true mate away to speak. “I know that you didn’t choose this either, that this was an arrangement between our fathers. So I agree to mate and marry you. And I would like to try to be friends too.”

Magnus wiped away the tears that threatened to fall and the sweat that had started beading on his forehead. His heat was starting. He already felt warm and the first tingles that would lead to the cramps were starting. Cramps that would only be satiated with an Alpha’s knot.

“Actually, I did choose this. You were supposed to be mated to my younger sister as she is an Alpha too. But she has already found her true mate, a commoner. And my magic is stronger than hers so I volunteered to take her place. It was the only thing I could do to protect her from this,” Alec said, breathing deeply when a divine scent reached across the room from the Prince.

“You would do that, to protect her?” Magnus asked, spinning on his heel to look at the man who was to be his mate. He had to reach out for the wooden frame of his bed when a wave of dizziness swept through him, unsure of whether it was from his heat or the fact that he was looking at his mate. His true mate. 

“It’s you?” Magnus gasped out, his knees almost giving out on him. The Sea Witch was his mate, dressed in a moss green robe that was similar to his own, complete with shining golden crown- encrusted with pearls- and seashell necklaces and bracelets. His mate looked just as beautiful in his human form as he did in his true form.

“You’re my mate?” Alec said, gripping the handle of the door almost tight enough to rip it off when his mate turned to face him. His mate looked stunning. And stunned. “But I thought… it’s you?” he asked, taking a step forward. When the Prince looked like he was about to collapse he crossed the large chamber swiftly.

“How? How is this possible?” Magnus asked, falling into the Sea Witch’s arms when he could no longer hold himself up. Nothing had ever felt more right then when he was encased in the strong arms that held him up.

“I don’t know. When I saw you today... when I was on my way here... My heart broke when I realized who you were to me. I had no choice but to let you go,” Alec said, staring at his mate’s beautiful face. It was hard to think with the scent that was emanating from the merman in his arms, something woodsy and exotic and utterly beautiful.

“Uh. I don’t know your name but I am Prince Alexander of Alicante. Or Alec, for short,” Alec said, pulling his mate to the bed and sitting him down on the edge of it. 

“Prince Magnus of Atlantis. But you can call me Magnus,” Magnus said, smiling when Alec knelt in front of him and checked him over. The cool hands on his face when Alec mopped his brow felt nice. Waves of heat radiated through him, making him uncomfortable in his robe.

“Nice to meet you, Magnus,” Alec said, smiling at his mate when Magnus leaned into his touch. “As I said before, I have no desire to force myself upon you. Magnus, will you be my mate?” he asked, fighting the desire that had started pulsing through him. Magnus smelled wonderful and his own body was reacting to Magnus’ hormones.

“Of course. If you want to be mated to me, that is,” Magnus said, meaning it with his whole being. In fact, he wanted to mate Alec now before his father burst in and told them that it was a big mistake and he was to mate Alec’s sister after all. He was sure she was nice but Alec was his mate.

“Absolutely,” Alec grinned. He had wanted it the moment he had lain eyes on Magnus earlier that day. “Are you okay?” he asked when Magnus started plucking at the pretty blue robe he was wearing. He felt Magnus’ temperature again, wiping the sweat from Magnus’ burning brow.

“Hot,” Magnus muttered. Before he knew what he was doing, he was pulling at the clasp that held his robe together with shaking hands. He stopped himself, searching Alec’s eyes to be sure he was okay with it.

“Which one is your washroom?” Alec asked, looking around for the source of the sound of falling water. There were two more doors, beside the main entrance. When Magnus indicated the door to the righthand side of the bed he helped Magnus stand.

Magnus knees went weak when he stood up. The combination of his heat and Alec’s proximity made him dizzy once more. He didn’t utter a word of complaint when Alec scooped him up, bridal style. Unable to stop himself, he wrapped his arms around Alec’s neck and buried his nose in the side of Alec’s throat, beneath to the three gill-scars, inhaling his beautiful scent. It was musky and strong.

Alec carried Magnus around the bed swiftly, trying to ignore his body’s reaction to holding the sweaty Omega in his arms. And from the way, Magnus’ nose skimmed up his throat. He kicked the washroom door open and stepped inside. When his eyes landed on the waterfall in there he went straight for it.

Magnus shuddered when the cold water cascaded over his body. It cleared his head enough for Alec to stand him up. A sigh of relief escaped him when he didn’t collapse into a heap. The heavy robe he wore was even heavier under the water and felt like it was rubbing his skin raw.

“I’ve got it,” Alec said, knocking Magnus’ shaking hands out of the way when the Omega fumbled the metal clasp on his robe once more. He undid it easily, pushing the heavy robe off his mate when Magnus nodded. His eyes swept over Magnus’ naked body when it was revealed. He had seen a hint of it through the sheer material but seeing Magnus in the flesh was a thousand times better. 

“Will I do?” Magnus asked shakily, pressing himself closer to Alec. He needed to be close to the Alpha, preferably skin to skin. The freezing water that cascaded over his back and shoulders was nice but he needed the Alpha more than the cool water right then.

“Do? You’re beautiful,” Alec muttered, sliding his hands around Magnus’ waist to pull him closer. He undid the clasp on his own robe when he saw Manus’ wince, the pearls scraping Magnus’ skin. “I’m having to fight to keep my tentacles inside me,” he said. 

“Why would you do that?” Magnus asked, sniffing at Alec’s neck as he helped Alec out of his soaking robe. It looked beautiful on him but it would look better on his washroom floor. 

“Because I don’t want to make you uncomfortable,” Alec said, shuddering when Magnus’ body was pressed to his own. The dilation of Magnus’ pupils, from slits to wide, round circles, and the scales that framed Magnus’ stunning golden eyes, shining in the dim light, almost stole the last of his will. 

“No such thing,” Magnus muttered, skimming his hands over Alec’s hips, willing him to get them out. “When I touched that one tentacle earlier… it was… I’ve never felt anything like it,” he said, remembering the shock and the desire that had flooded him, much like it was doing now. 

Alec couldn’t have kept his tentacles inside him if he’d wanted to. Just that touch on his hips was enough to snap his will in two. His hips jolted forward reflexively when he let them out, his eyes slamming shut when Magnus’ solid cock grazed his own hard length. 

“Fuck,” Magnus muttered when he felt Alec’s length pressed against his own. Taking a step back, he took in Alec’s gorgeous body with one sweep. The tentacles that slid out of Alec’s hips were breathtaking. He laughed when two of them curled around his arms and tugged him closer to his Alpha once more. 

“Sorry, I can’t help it. Your scent… your body…” Alec mumbled, trying to force his tentacles to unwrap from around Magnus’ arms. Unsuccessfully. He could barely think with Magnus’ scent getting stronger by the minute.

“Don’t apologize,” Magnus murmured breathlessly, tilting his head back when one tentacle tugged at his chin. Two more tentacles slithered over his hips and down the back of his legs, wrapping around them. The last three snaked around his waist and hips and pulled him flush to Alec’s body. The sensation of being pulled against his Alpha had an involuntary moan escaping his lips. 

Alec dropped his head, pressing his lips gently to Magnus’. Well, he tried to be gentle but it seemed the move was too much for Magnus’ self-control. 

Magnus wasn’t sure if he surged forward or if the tentacles pulled him but he wrapped himself around Alec’s body. The tentacles that held him up wrapped his legs around Alec’s waist. He wasn’t complaining, his body was begging for it.

Waves of desire and need crashed through Magnus when he flicked his tongue over Alec’s plump bottom lip. He pushed his tongue into Alec’s mouth as soon as his Alpha opened up for him, his hands finding purchase in Alec’s wet hair. A shiver ran down his spine when Alec kissed him back just as hungrily, a deep growl rumbling through his Alpha. The sound had his hormones going haywire.

The sudden cramp that shot through him jolted Magnus’entire body, forcing him to break the kiss.

“Magnus, are you okay?” Alec asked, his tone low and gravely. The whimper that came from Magnus almost turned the words into a growl. He gipped Magnus more securely when Magnus started grinding against him, the Omega shaking in his arms.

“I need you to knot me, Alexander,” Magnus said, pulling Alec into another bruising kiss. He panted into Alec’s mouth when Alec’s hands wandered over his back and ass. Every part of him was aching, from his joints to his skin. The aches were nothing, however, compared to the deep need that was growing inside him.

Alec realized how far gone Magnus was when he brushed his hand over Magnus’ ass. It wasn’t just water that spread over his fingertips, there was slick too. Magnus was practically dripping.

“Do you want to move to the bed?” Alec asked, removing his fingers to take Magnus’ chin in hand. Magnus’ eyes looked glassy when he looked into them. His Omega couldn’t even speak, just nodding before burying his face in his neck once more. 

Alec staggered back, carrying Magnus back into his bedchamber. When he reached the bed, Magnus scrambled down on wobbly legs and threw himself onto it, burying his face in the mattress. His mate didn’t even dry himself off first. Then again, they would be making a mess of the sheets anyway. The sight of Magnus, practically waving his ass in the air, had him crawling over his mate, almost pouncing. It was a beautiful sight.

“No time for that,” Magnus breathed, trying to rock back on Alec’s fingers when they probed at his hole. His body had taken over, preparing itself for his Alpha. Even as he said the words he could feel himself loosening up. Arching his back, he buried his face in the crook of his elbow when two of Alec’s fingers pushed into his ass anyway. His body begged for it, for more.

“I’m not just going to fuck you. I have to make sure you’re ready first,” Alec growled, his hips rocking forward, cock trying to get at Magnus when he felt how tight and wet his mate was around his fingers. If he was being honest with himself, he wanted to bury himself to the hilt in his Omega but he wasn’t a complete animal. 

The tight clench around Alec’s fingers almost tested that resolve but he fought himself to make sure Magnus was prepared. Spreading Magnus’ legs wider with two of his tentacles, he worked his fingers in and out of Magnus’ ass, twisting his fingers with every thrust.

“More!” Magnus demanded, too far gone to monitor what was coming out of his mouth. He tended to get a little demanding when he was in heat but was usually too riled up at this point to care. When Alec’s touch turned more insistent, his Alpa’s fingers curling inside him, he started rolling his hips, trying to fuck himself on Alec’s fingers. 

“Alexander, I need more. It isn’t enough,” Magnus whined, desire and need curling through him once more and setting him on edge. While Alec’s fingers were long, two of them didn’t even come close to an Alpha’s knot. Every cell that made him up needed Alec to fuck him hard and fast. To fill him with a knot and fuck some babies into him.

“You want more?” Alec growled, losing control of himself completely. His hormones and his body took over. The scent of Magnus’ slick and his tight, warm body around his fingers, shut his brain down.

Alec pulled his fingers out of Magnus’ ass, breathing hard when he saw Magnus’ loose, clenching hole, puffy and desperate looking. He badly wanted to lean down and lick the slick out of him but he focussed. Gripping his cock, he teased the head of it up and down his Omega’s crack. It didn’t take long to find Magnus’ dripping hole.

The moan that ripped from Magnus was indecent when Alec pushed into him, right up to the base with one quick, smooth thrust. If there was any pain he was too far gone to feel it. The tentacles that wrapped around him were more than welcome. They slithered over his skin, pushing his chest down, pinning his arms to the mattress, pulling his hips up further, spreading him wider for his Alpha. It was everything he needed. 

Alec gripped Magnus’ asscheeks, spreading them when he withdrew his hips before slamming into his Omega’s tight ass once more. His breathing turned shallow from the squeeze and the slick that started dripping down his own thighs every time their hips met.

Magnus couldn’t even speak. The pace his Alpha set was perfect, Alec pounding into him. With each thrust, every time their hips met, a loud clap of skin meeting skin rang through the room. He bucked his hips up each time Alec thrust back into him, trying to match his pace to Alec’s, trying to take him deeper.

“Closer, Alexander. I need more,” Magnus moaned, feeling hot and shaky. He reached back, grabbing Alec’s hips, trying to pull him closer. The need to feel Alec all over him, pressing him down and owning him was almost unbearable.

Alec stopped his break-neck pace, pulling out of his Omega for a moment. The whine that escaped Magnus tore at him but he maneuvered them so Magnus was lying on his stomach, his knees bracketing Magnus’ thighs. 

Draping himself over Magnus’ body, Alec gripped his dick and found Magnus’ hole. The squeeze was like nothing else he had ever felt. Magnus’ legs were pressed together beneath him, leaving him little room to fuck into his Omega. But the position allowed him to cage his mate in.

“Thank you, just like that,” Magnus muttered, arching his back and lifting his ass a little so Alec could fuck him. He tilted his head to the side when Alec’s hands pushed under his torso and curled over his shoulders. The soft kisses that Alec pressed to his gills and scent glands were nice but the rutting thrusts into his ass were nicer.

Magnus fucked into the mattress while Alec fucked into him. Waves of heat once again radiated through him now that he wasn’t under the cold water in the washroom but the almost painful need to be fucked hard was being satiated by Alec’s deep, hard thrusts.

“Is this okay? Is it how you wanted it?” Alec panted in Magnus’ ear, snapping his hips forward, again and again. A smile tugged his lips up at the corner when Magnus moaned a “yes” and tried to turn his head enough to kiss him. 

Alec was caging Magnus in too tightly for that, rutting into his Omega almost as desperately as Magnus was to be fucked. Instead, he pressed harder kisses to Magnus’ gills and neck.

Magnus shoved his hand beneath him, taking his dick in hand. While he couldn’t jerk himself off, each thrust of Alec’s hips jolted his body up slightly so he held on with a firm grip and let the motion do all the work. 

“Feels so good,” Magnus mumbled, breathing heavily. When Alec’s hand slid down his arm and grasped his hand, he interlocked their fingers, finding Alec’s rhythm and syncing his own hips to it.

“It feels amazing,” Alec replied, getting closer to the edge by the second. He could already feel the tension at the base of his cock, knowing that his knot would start swelling at any moment. 

“Are you ready to complete the mating?” Alec asked, letting Magnus know that he was about to knot him and making sure Magnus was okay with receiving his bite.

Magnus offered his right wrist up to Alec, getting close himself. Feeling Alec’s breath on his wrist, when Alec took his hand, sent a shudder skittering down his spine. Once they exchanged mating bites they would be mated and could merge their magic to create new wards for the Kingdom.

“Fuck, Magnus!” Alec grunted, pressing a desperate kiss to Magnus’ wrist when his knot started swelling. Slamming his hips forward, he pushed the engorged base of his cock into Magnus before it got too big. When his teeth sharpened to points, he sank them into Magnus’ wrist, wincing when Magnus cried out.

Alec offered his left wrist to Magnus when his knot expanded fully, cumming hard inside his mate with grinding jerks of his hips.

Magnus came when Alec spilled his seed into him, rutting against the knot that filled and stretched him so perfectly. His own teeth sharpened enough for him to bite into Alec’s left wrist, marking the Alpha as his own. A wave of Alec’s cum shot into him, making him jerk happily in the tight cage of Alec’s arms.

Magnus could barely breathe with Alec’s heavy weight on top of him but he didn’t mind so much. His body was starting to cool down and the need to be pregnant abated a little more with each load that Alec expelled. He knew it wouldn’t last but for the moment, he felt satiated. 

“I’m going to roll us over,” Alec said, fighting to get his breath back. His balls spasmed when another spurt of cum erupted from the end of his cock. Hopefully working its way into Magnus’ womb. Although, he wouldn’t complain if it took the entire three days for Magnus to get pregnant. He untangled his tentacles from Magnus and moved as gently as he could.

The tugging sensation in his rim wasn’t pleasant but Magnus could breathe easier when he was lying on his side with Alec still buried in his ass. He settled into the embrace of Alec’s arms and tentacles, ignoring the damp patch they were lying in. They would both be covered in slick and cum before they were done.

“How do you feel?” Alec asked, placing his hand on Magnus’ forehead. His Omega still felt warm but he wasn’t boiling hot. 

“Better. Much better,” Magnus said, his eyes closing when Alec’s cool hand ran across his forehead and cheeks. A smile tugged at his lips when he felt Alec’s hips jerk against him.

“When did you find out about this?” Magnus asked, opening his eyes to inspect the mating bite on his wrist.

“A messenger from your father turned up in Alicante two weeks ago. I overheard my parents talking about his request that you be mated to one of their children. They wanted to keep me around to take over Alicante when it was time but I convinced them to send me here in the end. I couldn’t let Isabelle mate someone that wasn’t her mate,” Alec said.

“But you could sacrifice your own?” Magnus asked, plucking at the seashell bracelet that adorned Alec’s wrist. The thoughtful act tugged at his heartstrings a little. It was nice to know that his mate was so selfless. It was what his Kingdom needed desperately. Even if it could have gone wrong for them.

Magnus lay his own wrist next to Alec’s on his pillow, inspecting their matching bites. His stung a little but he already felt as though his magic was stronger. Another thing that his Kingdom was in desperate need of.

“I hadn’t met you yet,” Alec said, peeking over Magnus’ shoulder. “I always thought I would be mated to someone from my own Kingdom. When you never turned up and swept me off my feet I took Izzy’s place,” he said.

“I’m glad you did,” Magnus said, looking over his shoulder to meet Alec’s gaze. The warmth he saw there, along with the blinding smile made his stomach flutter. His mate was so handsome. He had really gotten lucky. 

“What would your father have done if mine had said no?” Alec asked, skimming his hand over Magnus’ ribs and hip. He couldn’t help himself, Magnus was too beautiful. He wanted to touch every inch, to learn his mate’s entire body.

“He probably would have sent a messenger to Edom,” Magnus said with a shudder. It was a well-known fact that Prince Jonathan of Edom had strong magic too. The three Kingdoms stood equidistant from each other, forming what the humans called the Bermuda Triangle. Once a human ventured into the midst of the Three Kingdoms, they didn’t return. The strong magic that infused each Kingdom saw to that.

A low growl escaped Alec at the thought of Magnus being mated off to Prince Jonathan. There wasn’t a doubt in his mind that he would have fought Jonathan with everything he had to keep Magnus away from him. It was rumored that Jonathan had a vicious streak. 

“You came instead,” Magnus said, snuggling back into Alec when his Alpha’s arms and tentacles tightened their grip around him. “So, you’ve had a couple of weeks to get used to the idea of having a mate and children. And taking over a Kingdom. How do you feel about it?” he asked.

“I never really thought of having children. Not yet anyway. I’m only 136. But I know that they won’t let us out of here until you’re pregnant. I won’t lie, I hated the thought of coming here and mating someone who wasn’t my mate. But I’m so glad it was you. And I know we can figure out this parenting stuff together,” Alec said, burying his face in Magnus’ scent glands.

“I found out today. Honestly, I hated the thought of mating someone and having children with them when there was a strong possibility that I could never love them. It scared the shit out of me. When I turned around and saw you, all I could feel was relief. It doesn’t scare me as much now, knowing that we will have a loving relationship, that we will be able to raise children in a stable home,” Magnus said.

“Me either. As for inheriting a Kingdom, I’ve been prepared for that my entire life. It will just be a different Kingdom now,” Alec said.

“We need someone that is compassionate here, Alexander. Our people are wonderful but my family… the way they’ve treated them… I don’t want us to rule selfishly. I want us to give our people a good life and a monarchy that they can be proud of, if not love,” Magnus said, meeting Alec’s gaze over his shoulder once more. 

“Of course,” Alec said, pressing a kiss to the corner of Magnus’ lips. He had heard rumors of what this Kingdom was like and had come here determined to change things. He was glad it was Magnus he was mated to and not one of his notoriously selfish siblings.

“We can banish the rest of your family to the lowest levels of this mountain if you like?” Alec suggested, grinning when Magnus burst into a fit of laughter. It did interesting things to his dick where it was still buried in Magnus’ ass. His knot was starting to deflate a little so he held Magnus closer for a few moments more.

“I’m seriously considering it. Let’s wait until we’re on the thrones first,” Magnus said. A laugh escaped when Alec pressed kisses to his gill scars, his Alpha’s breath ticking over his neck.

“My knot has gone down. Are you ready?” Alec asked with a sigh. He didn’t want to pull out of his Omega. He was quite happy where he was. 

Magnus nodded, wincing slightly when Alec pulled out of him. He let Alec pull him from the bed, his legs a little shaky and cum dripping out of him. But he was able to stand. “You really are beautiful,” he said when he got another look at his mate’s sublime body.

“Look who’s talking,” Alec chuckled, shamelessly ogling his mate. The task at hand eventually stole his attention but not before he had gotten a long hard look at every inch of Magnus that he could see. It was like a feast for the eyes.

Magnus took Alec’s left hand in his right, entwining their fingers as he turned to look out over the town that filled the interior of their Kingdom. When the insides of their wrists pressed together, their bleeding mating bites pressed flush together, he began the task of merging his magic with Alec’s. 

A beatific smile tugged at Alec’s lips when his magic mingled with Magnus’. While his own magic was stronger, Magnus’ was more unique. He knew there were many things that Magnus would be able to teach him and vice-versa. When they were done, he started quietly muttering ward spells under his breath, his mate doing the same.

Magnus helped Alec direct their combined magic into the wards that surrounded the Kingdom. Alec weaved it together and he sent it out. When it was done, he felt lighter than he had done for a long time. The wards were once again strong and his new magic was breathtaking. 

“Your Kingdom is beautiful,” Alec said, wrapping his arm around Magnus’ shoulder to look out over the stunning view that lay before them.

“ _ Our _ , Kingdom. I hope you’ll be happy here, Alexander,” Magnus said, taking Alec’s hand in his. He healed their mating marks before sinking into Alec’s side. 

“I have no doubt that I will,” Alec said, gazing at his mate. The view of the Kingdom was spectacular but it was nothing compared to what he saw when he looked at Magnus. He silently vowed to ensure Magnus and their children had the happiest life he could possibly provide.

Each of Alec’s tentacles pulled Magnus to him, wrapping around his mate’s body in a fierce embrace. He laughed when Magnus twined his hand in the shell necklace that adorned his throat and tugged. He happily sank into Magnus’ kiss, knowing that he would be very happy indeed.

And so the Kingdom of Atlantis was saved. 

Prince Magnus and Prince Alexander mated constantly for two days until Magnus’ heat ended early. Pregnant with the first of many children, Prince Magnus married his mate in front of the entire Kingdom and in the presence of their families. 

The Kingdom thrived under the rule of King Magnus and King Alexander. 

The previous royal family was banished to the depths of the mountain as punishment for their ill-treatment of their people. 

An alliance was forged between Atlantis and Alicante when Princess Isabelle Married her mate, Maia. Under the care of Queen Isabelle and Queen Maia, the Kingdom of Alicante prospered as much as Atlantis did.

And Alec and Magnus lived happily ever after, surrounded by their children and subjects. 

The End.

**Author's Note:**

> And that's the last of Tentacletober. It's been a ride! Thanks to everyone who read my contributions. If anyone wants to write more of this last chapter feel free. But please link me. Personally, I wont be continuing it so it's up for grabs if anyone feels inspired.


End file.
